The battery is 12 mutations, one freshly copied tree each, purged, `:ro`,
`python3 -B`, byte deltas measured. First round: 9 red, 3 survivors. All three
are now accounted for and the ledger is in DECISIONS §8.
M5 - `share <= 0` relaxed to `share == 0`, +0 B - WAS A REAL GAP AND THE TWO
OBVIOUS CHECKS DID NOT CLOSE IT. `short_by(-2000, 0) is None` and
`short_by(-2000, -100) is None` both stayed GREEN under the mutant: for a charge
share that is UNDER-delivered `share - measured` is negative and the `gap > 0`
test answers None anyway, so neither input can separate the two spellings. The
one that can is a unit moving MORE than its charge share - -2000 W told,
-3000 W measured, `share - measured` = +1000 W - which the mutant reports as a
shortfall. It is not one; it is something else driving that pack, which is
SAFETY-30's and SAFETY-31's question. That input is now the check, and M5 is RED.
MUTATION.md's third failure mode in miniature: the assertion ran, the sentence
was true, and the data could not reach the failure it named.
M11 - `inv.is_live(now)[0]` replaced by a literal `True`, -15 B - was a WIRING
gap the pure checks structurally could not see. `account(live=False, ...)` was
graded as a FUNCTION; nothing graded that `cycle()` asks the question, because no
fixture had a unit whose writes were being rejected. Such a unit still has its
last ACCEPTED command standing on the wire (`write_setpoint` leaves `last_write`
alone on a rejected write) and still measures nothing, so it looks exactly like a
wedged one to every number this check reads - and reporting it would be the
second, louder alarm about a state the allocator has already handled and logged.
`test_delivery.py` part 6 now builds that unit, with `rejected_since` back-dated
past LINK_STALE_S because the fixture runs in two seconds and the timer is
test_inverter.py's to grade. M11 is RED.
M3 - `len(asked) < 2` relaxed to `< 1`, +0 B - IS STILL A SURVIVOR, and it is an
EQUIVALENT MUTANT. With one asked unit `unaccounted` is a subset of a one-element
set, so it is either empty (`not unaccounted` returns {}) or equal to `asked`
(`len(unaccounted) == len(asked)` returns {}); with zero asked units both
spellings return {} as well. No input separates them, so no check can.
⚠️ AND FINDING IT CORRECTED THE MODULE'S OWN PROSE, WHICH IS THE MORE USEFUL
HALF. `delinquent()`'s docstring claimed `len(asked) < 2` was what makes N=1
inert. It is not - the PROPER-SUBSET rule is, and that line is a fast path and a
signpost. A false attribution of the mechanism in the file's own prose is exactly
what this repository keeps finding, and a mutation that survives is how it
surfaced. The line stays, with the equivalence written down beside it the way
circulation.circulating_w() records its own max(0.0, ...).
Also recorded, rather than left implicit: `account()`'s `parked` branch is graded
as a function but its WIRING is not mutated on its own; part 6's reversed-unit
fixture exercises it end to end, which is weaker, and the ledger says so.
Baseline 23/23 green before and after. app/main.py is byte-identical to the
previous commit - both closures are a test and a comment.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
